1. Field of Invention
The present invention relates generally to methods and apparatus for use in pressure washing. More particularly, the present invention relates to methods and apparatus for safely washing objects with a pressure washer and recovering contaminants from the objects.
2. Background
Contamination of the environment by man-made substances has been considered a serious problem for a long time. Recently, concern about contamination of earth, air and groundwater by oil, toxic chemicals and other hazardous wastes has expanded beyond large-scale industry to encompass the activities of many small businesses such as automobile service stations, and many others. Both government regulations and social outcry have placed tremendous pressure on these businesses to avoid discharging hazardous wastes into the environment in the course of ordinary business activities.
For example, in a service station, washing or steam-cleaning an automobile engine or auto parts often causes engine oil, gasoline, and other chemicals to enter a storm drain system, or other waterways which can lead to contamination of earth or groundwater. In addition, those who service remotely located equipment have a need to wash the equipment without discharging hazardous waste into the environment. For example, persons who service roof-mounted air conditioners containing lubricating petrochemicals, trapped pollutants or other chemicals are not permitted to wash the equipment in a manner that could cause chemicals to run off.
High pressure washing equipment is available, but in general, existing pressure washers have no containment capability for hazardous materials. They cannot prevent hazardous materials from entering the surrounding environment. Even if all the wash fluid is somehow recovered, hazardous wastes are not filtered out, so that these systems generate an enormous volume of wastewater which must be processed separately or placed in barrels for disposal.
Thus, there is a tremendous need now for a portable, zero-discharge wash apparatus which can recover oil, chemicals, and other hazardous materials from an object which is washed. In addition, there is a serious need for a wash apparatus which can recirculate and repeatedly filter the washing agent, producing a very small quantity of waste material, and for a wash apparatus which overcomes other disadvantages of the prior art, and provides other needed features, as for example splash protection for an equipment operator.
Known pressure washing equipment has other serious disadvantages. For example, such pressure washers are ordinarily connected to a public water supply having unknown average pressure and unknown instantaneous pressure. Fluctuations in pressure of the public supply could cause damage to the pressure washer or render it unable to produce consistently high output pressure. In addition, even when the public supply has consistent pressure, its pressure may be outside an ideal operational range for the pressure washer. Therefore, what is desired is a portable, self-contained way to conveniently and safely wash objects, e.g., automobile engines or parts, and recover contaminants from them by providing a controlled water supply to an adjustable pressure washer. Further, it is also desired to provide a pressure washer that reduces operator risk which can result from close contact with contaminants.